Certain cable transportation systems which move vehicles along a given track are described in documents: Swiss Patent Document CH 671,929; Austrian Patent Document AT 404,010; U.S. Pat. No. 5,582,109; European Patent Document EP 687,607; Austrian Patent Document AT 405,269; European Patent Document EP 1,077,167; European Patent Document EP 1,088,729; Italian Patent Document IT 1,313,914; Italian Patent Document IT 1,317,169; Italian Patent Document IT 1,316,131; Italian Patent Document IT 1,326,531; PCT Patent Application Document WO 08/129,019; PCT Patent Application Document WO 2009/019,259; and PCT Patent Application Document WO 2009/053,485.
The tracks of certain of these cable transportation systems sometimes have at least one junction. One particular type of junction is where the track splits into two at a stop station for two vehicles travelling in opposite directions.
Cable transportation system tracks may comprise two-way and one-way sections, along which the transportation units pass one another in opposite directions.
Certain known cable transportation systems comprise two haul cables, which are operated in opposite directions, extend parallel to the track, between two opposite guides, and are connected to the transportation units by clamps integral with the units.
Certain known cable transportation systems therefore require switches, which, in addition to ensuring continuity of the track, must also avoid interfering with the haul cables and clamps.
One example of a known switch for cable transportation systems is described in Italian Patent Document IT 1,326,531, and comprises a track section defined by two curved, parallel rails extending along respective arcs of a circle and mounted on a pivot. The curved rails are designed to connect different branches of the track, depending on the angular position of the pivot. Though effective, this type of switch has the drawback of having a very large, extremely heavy moving part, such that switching tracks involves a good deal of travel and, therefore, time.
Other types of cable transportation system switches are described in European Patent Applications EP 2,407,366 and EP 2,441,636, in which at least one movable guide, with one degree of freedom along an operating plane, is moved between two given positions by an actuating system comprising a linear actuator.
The switch described in European Patent Application EP 2,407,366 has the advantage of being extremely simple and minimizing the moving mass, but does not allow for switching tracks along curves.
Conversely, the switch described in European Patent Application EP 2,441,636 has four movable guides for switching tracks along curves, but has a considerable moving mass that projects outwards of the track.